How He Got Into My Head
by everybodylovespercyjackson
Summary: Its Annabeth’s eighteenth birthday. Her mind is in her soulmate’s body and the same for him. When he gets a bad impression from her roomate and messes up her life, he intends to make it right on his birthday.
1. Chapter 1

Notes: I got this idea off of Pinterest (and I'm pretty sure it came from Tumblr), so the idea itself does not belong to me. I'm not quite sure who it does belong to, but I wrote this story. I did change a few things to make the story flow better. Enjoy!

 **Annabeth's POV**

Annabeth was studying hard. She was in fact staying up close to midnight. Piper and Reyna had tried to get her to go to sleep. "All this studying won't do you any good without resting!" They echoed over and over again. Annabeth wanted to, she just couldn't. If she failed this exam there was no way she would get into that college with the excellent Architecture program.

"I'm so tired," she whispered to herself.

"Maybe going to sleep would help?" Nico di Angelo said from outside the door.

Annabeth jumped. She was staying with her friend, Hazel, while her father was off on vacation with her step brothers. Annabeth had chosen not to go for the benefit of good grades. The only downside to staying with a caring friend was the brother that popped out of no where.

Don't get her wrong, Annabeth adored Nico. He was wise and sweet. His boyfriend, Will, always gave her tips to stay healthy. But if he would just _not_ pop out of no where sometimes, she would definitely have more positive feelings about him.

"Tried. I'm too stressed," Annabeth made an excuse.

Nico's eyes glazed over with thought. "Is it because tomorrow is your birthday?"

"Yeah. What does that have to do with anything," Annabeth panicked with confusion. _What could possibly be so stressful about her birthday? It happened once every year._

It's your eighteenth birthday," Nico pointed out and emphasized with a half-hearted hand gesture.

Annabeth melted with dread. On everybody's eighteenth birthday they would take the body of their soulmate. That meant that her body would go through the same thing. Somebody was going to take over her body too. She would have no say. However, she would be in some strangers body, hopefully not screwing up their life. She was always so afraid that one day somebody would appear in her body randomly.

When she turned back to respond, Nico was gone. She assumed that she imagined it and that her birthday was not going to be tomorrow. She glanced at the clock. Too tired to read it, she dozed off and fell asleep.

The next morning she woke up. She was not in her room. In fact, it wasn't even _her real_ room. Annabeth was the lying in the bed of a teenage boy. She bolted up. She panicked and lifted up the sheets. _She wasn't even in her own underwear!_ She got up and saw herself in a mirrors- only she wasn't herself.

She was a boy with dark hair and sea green eyes. He was tall, it muscular. Annabeth spotted an expo marker by the mirror. She uncapped it and began to write things on the mirror. She was almost done when a woman came in.

"Percy, what are you writing?" She glanced at the mirror. Then her face lit up. She looked like a proud mother. The woman grabbed Annabeth's arm and dragged her to the living room.

"It's your birthday? Happy birthday sweetie! Your name is Annabeth? I'm making you a cake!" The woman fussed and ran about the room.

"Um, who am I?" Annabeth squeaked. Her voice was low, but graceful.

"You are my son. Your name is Percy Jackson," Mrs. Jackson explained as she rushed around the kitchen. "You should go to school."

 **Percy's POV**

One second he was playing video games. The next he was sitting st the desk, jolting awake with a serious need to use the bathroom. He rushed through the house looking for a room with a toilet. Then suddenly a tiny person appeared next to him, scaring him so bad he almost peed right there.

"What are you looking for?" he asked.

"Bathroom," Percy muttered. The person lead him to the bathroom. As he was washing his hands he looked up and saw himself. When it clicked what was happening, he freaked out. _This beautiful woman is my soulmate?_ When he left and returned to the bedroom he almost lost control of his bladder again. Not only was she beautiful, she was crazy smart. He decided to go to bed, he would need to sleep so he didn't mess up this girl's life.

"Annabeth! Ugh, you are _so_ not a morning person!" a girl screamed. A tiny girl with golden curly hair walked in. Percy, however, was already awake. When the girl came in to a confused Annabeth going through her dresser looking for clothes.

" _Oh shit!_ " The girl screamed. "It's her birthday!"

The girl ran out of the room and came back with a packet of papers. She sat down next to Percy, stuck out her hand, and shook it introducing herself as Hazel.

"So Annabeth, being the smart-ass she is, prepared for this. I've go the outfit you can wear here...And she also has a form to fill out so she can find you," Hazel began to hand Percy things. "She also wants you to try not to get her killed today! Anyway, Nico can help get you to stay home today. Annabeth wouldn't like it, but you don't seem to smart and, in my opinion, you should stay here with him."

Percy did his best to try and understand it, but Hazel seemed to be in a rush. She probably had school. A guy walked into the room wearing nothing but black shorts. Percy hoped he wasn't the brother. Or the guy he met last night.

"Hazel, Persephone is gonna bring you to school," he said.

"Why don't you have to go?" Percy asked.

"Doctor's note," the boy winked at him.

Hazel got up and gave a brief eye roll at the comment. "Nico, can you stay home with him? I'll tell Persephone to call the school that Annabeth is sick."

"Ugh, fine. But if I have to babysit him while he fills out those papers Anna-"

"Excuse you? Babysit me? I'm not a child!" Percy interrupted.

Without skipping a beat Nico merely continued. "Promise to not get stuck at school. This person isn't going to sit here and we know it."

Hazel rolled her eyes for the second time that day. Then she quickly left. Nico turned toward him and gestured to follow him. They walked outside to the backyard. There was a large fence around it that nobody would ever be able to jump. They sat down at a table and Nico watched him began to work.

"Percy Jackson?" Nico asked.

Percy nodded and continued to work. He wanted to get this done. He was gonna figure out how to get back home so that he could meet her.

"I'm gonna get my phone," Nico said.

He walked back into the house and shut the door. Percy finished a little while later. He went to go back inside, but the door was locked. He pulled and tugged. He started to yell. Nico came to the door.

"What?" Nico asked. It was hard to be intimidating talking to a ghost boy almost his height.

"Let me in! It's hot out and I'm bored!" Percy demanded.

"Sorry Jackson. I have a doctors appointment later and I don't want you bothering me. Just stay out there until Hazel comes home," Nico walked away.


	2. Chapter 2

Percy screamed into the door for a few more minutes. He sat for what felt like hours until he heard a car door. He jumped up and stared in.

A man with blond hair and freckles walked in. Nico walked over and they kissed. Percy didn't feel comfortable watching this and didn't think the guy would help so he decided to work on a solution. He looked around the yard. There was basically nothing but a shed. The shed had a lock on it.

He dropped his head along with his hopes. He walked over to the lock and tugged. Then he remembered he was in Annabeth's body. She ought to have a hair pin. He found one in his hair and after a few failed attempts, picked the lock.

He was impressed with himself, but assumed it was muscle memory from this girls regular life. He couldn't lie, he found it _hot._ He walked in and found a few chairs and a table. They probably hadn't gotten to taking these out this year yet. If Percy was going to put his should on these in an attempt to get out, the most he could was take what wasn't being used and set it up.

He made the set up to look as nice as he possibly could and took what he needed from the set to make a makeshift ladder. He climbed over before realizing he still had the papers. He slid them under the door and left. He saw Nico look out the window at him. He flipped Nico off.

He ran down the road, afraid Nico was following him. It was Nico's job to make sure he didn't get himself killed. Nico was a bit of a creep to him. He seemed familiar however. Then it clicked. When Percy was thirteen, he went to the same school as him! Bianca, his biological sister, was in his grade. When they went on field trip, Nico asked Percy to keep an eye on her. Percy had failed, and Bianca had went missing. Everybody assumed she'd ran off to the boarding school that took in young females and trained them in combat for certain careers. Nobody had ever heard from her since. After a while of running Percy had gotten lost. He heard Nico yelling behind him. Nico quickly caught up to him. For a small guy he was incredibly fast.

"You don't know where you're going, do you?" Nico asked.

"Well I know I'm not going back to that house with you," Percy snapped.

Nico put his hands up in surrender. "I thought you would be a little more chill. Just- Annabeth is so uptight I assumed her soulmate would be the opposite. You're a bit..."

Percy waited for Nico to finish his sentence. When he didn't Percy went to keep walking, but Nico grabbed him and held him in place. This kid was really strong. Percy swung his arm out of his grip, but Nico kneed him in the leg and grabbed again. Percy turned and punched Nico in the jaw. Nico staggered back.

"Should not have done that," Nico shook his head.

"And why is that?" Percy looked down at Nico.

"The people here are big on protecting children. Lucky for me, I'm still a child in their eyes. However, they all know you're eighteen _Annabeth_ ," Nico hissed.

Percy's heart dropped. He was Annabeth today. He just messed up a girl's life forever. Then he realized he had a reason. Nico was basically holding him captive and then kicked him in an attempt to get him back to the house. He began to walk away from Nico smirking to himself. He would know what to do if they cops showed up. He had enough experience.

Percy went home and went back into Annabeth's room. He wrote down a list of things that happened to help her out. She didn't want Nico to be upset with her when it was him that did the punching. Hours went by. Hazel came home and Nico had locked himself in his room. Soon he went to sleep. He woke up in his own body the next morning.


	3. Chapter 3

Annabeth woke up in her own bed to the knock on the door. She knew exactly which neighbor knocked like that. It was her neighbor Mrs. Peterson. Mes. Peterson was that neighbor that got in everybody's business and acted like they owned the town. Annabeth went to open the door.

"Hi Annabeth! You're exactly who I'm looking for," Mrs. Peterson greeted.

"Why is that?" Annabeth asked.

"Well I saw you yesterday, punching little Nico, and I just wanted to warn you that it's not ok," Mrs. Peterson began. "If it happens one more time, I'm calling the police for domestic violence. I already called the school so they would keep an eye on you."

"Excuse me?" Annabeth asked in a rude tone. "Next time you _see_ something, talk to me! It was my eighteenth birthday yesterday."

Mrs. Peterson looked horrified. She quickly apologized and rushed home. Annabeth knew she wasn't really sorry. Annabeth went back to bed and thought about how lovely her experience had been with Percy's family. How could Nico screw Percy's up so bad that Mrs. Peterson had to call the school?

When Annabeth arrived at school she was immediately called to the Principal's office. She sat down politely, knowing she had not done anything wrong. Even if she had, she would've developed a pretty good lie to keep herself out of trouble.

"Annabeth, what was that yesterday? Punching Nico?" The principal asked.

"It was my eighteenth birthday yesterday," Annabeth barely spit the words out before the principal apologized, explaining it wasn't his idea it was Mrs Peterson.

As she left the room she heard the principal dialing numbers and having a pretty heated argument with her neighbor.

She walked to her normal classes. Students looked at her with wonder on how sweet, innocent Annabeth could ever do that. Annabeth didn't mind these looks. She even found it funny. However, when she got to art, the teacher did not find it so funny.

"Can everybody please get to work on this? Annabeth is not that much of scene to distract you _all_!"

Annabeth blushed. Her teacher had basically just put more attention on her, and Annabeth was starting to notice the negative ones. She knew she would, she was just hoping it wouldn't be until after lunch.

She goes to lunch and sits next to Piper and Rachel. They look at her with concern. Annabeth already knows why.

"Has anybody brought it up to you?" Rachel grabs her hand for support. They weren't used to social drama. They liked to be the quiet friends.

"Only my art teacher. She can't _ever_ let me be," Annabeth vented.

Piper shook her head. "If anybody messes with you, I know you can handle yourself, but just tell me. Everybody does what I say so I'll get some jock to beat them up."

They laughed. This made Annabeth relax. Her grades were fine, her excuse was accepted by everybody, and none of her friends seemed to be betraying her.

As she walked into the gym, Octavian approached her. _Great_ her least favorite person.

"So you punched a kid?" Octavian asked.

"It was my eighteenth birthday," Annabeth said and she tried to walk away.

"Ok, but how does that make it better?" Octavian blocked her way.

"Look, I don't want to talk about this with _you_ ," Annabeth spat.

"Then I guess I will spread fake rumors?" Octavian pushed Annabeth back up against the wall. "No matter what you say, ill spread rumors. But maybe if you..."

Annabeth slapped him. This rat would not treat her this way. He looked back and cracked his knuckles, preparing for a fight.

"Is there a problem, Octavian?" Annabeth's boyfriend, Luke, came out. He towered over everybody and spoke louder than a screaming crowd.

Octavian scowled and walked off. Luke turned toward Annabeth and gave her a hug. In silence they walked to the edge of the bleachers and sat down without talking. Luke gave her a tired look.

"Remember on my eighteenth birthday, how I was in some other girls body? And now you were in some other guys? Should we even try at this point?" Luke asked.

A tear trickled down Annabeth's cheek. Luke wiped it away and kissed her forehead apologetically. "Luke, can we try? Please?"

Luke smiled down at her softly. "I will always love you, Annabeth. We will always be family. But if we're destined to end...why not make it peaceful? I _promise_ we will always be family."

Annabeth nodded and leaned against his shoulder. He gently stroked her hair. They sat still for a moment. Luke noticed the damp spot underneath Annabeth's head. He pulled her closer. "I'll always love you."

"Don't say that," Annabeth begged as she snuggled her face into his neck. Luke laughed. He rested his head against hers. Then gym began.

 _This was it_ her life was totally ruined. Nothing could ever fix the problems that _Percy Jackson_ had caused. She was now a public menace and a single girl.

When she got home all she wanted to do was punch Nico. She almost did until she remembered that she wouldn't have an excuse for that. Annabeth sat on her bed and cried into her pillow.

"Annabeth, what's wrong, sweetie?" Piper asked from the doorway. Behind her, Hazel held a tray with three hot chocolates on it.

"Nico totally ruined my life! I've lost Luke! I lost the respect of so many people! Oh my god..."

Nico stepped into the room. "Luke? You didn't know he was moving to California with his Great Grandfather, Kronos? Strange name, but still."

Annabeth looked up and glared silently at Nico. Piper nudged him in the side to signal to get out. Nico, however, stood firmly in his spot.

"Don't look at me like that Annabeth. That guy chose to punch me," Nico defended himself. "Plus he has your number, right?"

Annabeth nodded but her grim expression didn't leave. Nico walked over and bent over to look her right in the eyes.

"Then text him."

"YOU COMPLETE IDIOT!" Annabeth exploded. "He didn't leave his number. Remember that sheet you managed to lose?"

Nico backed up. "I'll be right back."

Nico left and did not return for an hour. Or two. Or the entire night.


	4. Chapter 4

Nobody went to look for Nico. Everybody wanted to stay on Annabeth's good side. Plus they all assumed that he had went to his mysterious boyfriend's house that, so far, only Percy has gotten to see.

"Sweetie, please, Nico is so young and...well we think somebody should go find him," Piper tried.

Annabeth merely shrugged her off and continued to watch her sad movie. She was wrapped up in a blanket in her living room. A few tears had managed to escape. Hazel sat with her. Poor Annabeth.

Her eighteenth birthday was supposed to be a good day. She would meet her future lover and her life would begin to fall into place. However, everything was falling _apart_. The only thing Hazel could do was pretend that Nico didn't exist. Piper left on her search for Nico.

 **Pipers POV**

Nico has basically disappeared. Piper didn't know where the boyfriend lived and she was not going to endanger Nico's chance at love by asking the wrong person. Piper was often thought to not have genious ideas like this, but she did. She quickly stopped at the library and looked up Percy Jackson.

A few people came up but it was finally at the third one did bits of Annabeth's story fall into place. She quickly wrote down his email.

Piper: Hey I know you don't know me but I'm a friend of Annabeth's. I need to find Nico and Annabeth is being real moody about how he treated you. So could you tell me who his boyfriend is?

A half hour went by before a bit of a response came back.

Percy: Who is this?

Piper: Piper McClean. I kinda need you to hurry!

Percy: like the actor?

Piper:...yeah? Can we hurry this up!

Percy: oh yeah. He is um, a guy. Blond hair. Wore scrubs so he's like a doctor? Name was something like Will?

Piper immediately knew this guy. She was so surprised that a relationship like that existed that she almost drooled onto the computer.

Piper: Thank you so much! I'll give Annabeth your email my dude!

She left before Percy could respond. She hurried over to Dr. Solace's home. She quickly knocked. Dr. Solace was twenty eight and Nico was only, like, fifteen. This was totally wrong, but Piper was no snitch.

"Oh, Piper. How can I help you?" Dr. Solace asked.

"Nico." Piper requested bluntly.

"E-excuse me?" Will almost choked in his tea that he was drinking.

"Is Nico here?" Piper started to tap her foot in frustration.

"Why would he be here?" Will began to back away ever so slowly.

"Look, man, I know you're dating my bro. So could you do me a favor and tell me where he is?" Piper looked up expectantly.

"Um can you come in?" Will held the door open and Piper walked in.

They sat in the living room. Piper sat on the sofa while Dr. Solace took the chair. They had a few moments of awkward silence. Dr. Solace leaned forward and began to talk.

"How could- how did you find out?"

"Nobody who can do anything about it knows but me. And I'm not even gonna say anything. I just want to find Nico."

Dr. Solace grunted and took his phone out of his pocket. "If I call him he'll pick up."

"Wait, you mean he isn't here? Where the fuck is he?" Piper stood up and towered over the seated doctor.

"Calm down," Dr. Solace cooed. "He'll pick up." He was right. After an intense conversation and a bit of lying, Nico was tracked down to the cemetery.

"You can call me Will, by the way," Dr. Solace said.

"Okay," Piper replied. She really didn't want to be friends with her doctor. Nico must've really liked this dude and Piper wasn't going to drive him away. But she didn't want to get close to this weirdo.

"So, what's up with Nico?" He asked.

Piper shrugged. They walked the rest of the way in silence. The cemetery was quite beautiful and Piper had a hard time understanding how her little emo friend could possibly be sad in such a place. They approached Nico and when he saw Piper he didn't scramble away. He actually looked quite relieved.

"Nice place," Piper noted.

Nico nodded. Will went over and sat next to him. He wrapped his arm around the boy. Nico snuggled his head into Will's neck and whispered something. Will whispered back. If it were anybody else Piper would want to know what they were saying, but this was Will and Nico. She knew she would sleep better at night not knowing.

"You have his email?" Nico asked.

"Yes," Piper said.

"Good. Give it to Annabeth."


	5. Chapter 5

**Annabeth's POV**

Piper came back with a note and Nico right behind her. Nico seemed quite satisfied with himself, despite the series of issues he had caused. Annabeth sat up a little, as if to get a better view of the note.

"Annie, I got a present for you!" Piper squealed and jumped over the back of the couch to sit next to her.

"What is it?" Annabeth asked to humor Piper.

Piper opened the note and gave it to Annabeth. Annabeth screamed in delight. Hazel ran over to get a look at what the surprise was. Hazel smiled at Piper and walked away to finish what she was doing. Annabeth scrambled up the stairs to her to her bedroom and opened up her laptop and emailed Percy.

Annabeth: I'm so sorry! Its me Annabeth! How can I make your terrible day up to you!

A few minutes passed before she got a response.

Percy: A phone call.

Her phone buzzed next to her and she quickly picked up. It was Percy. They had a lengthy conversation.

 **Seven Years Later**

Annabeth wouldn't cry. She didn't promise herself she wouldn't. It was just that she had perfected her makeup for three hours and wouldn't let it be ruined by simple tears. She walked out and looked her father in the eyes. He took her arm and they began to walk.

"I'm proud of you," he said.

"I know," Annabeth replied. They reached the end of their walk and Annabeth continued on her own. When she saw him she let a tear fall and Percy wiped it for her.

"You look beautiful, if my dear bride!" Percy kissed her hand. Annabeth smiled.


End file.
